Condensed Consolidated Statement of Changes Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period (in shares) at Sep. 30, 2018			47,080
Balance at beginning of period at Sep. 30, 2018		$ 122,059	$ 472	$ (2,580)	$ 457,978	$ (317,373)	$ (16,438)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		26,949				26,949
Other comprehensive (loss) income		(2,721)					(2,721)
Stock-based compensation		2,982			2,982
Issuance of common stock (in shares)			131
Issuance of common stock		(695)	$ 1		(696)
Repurchase of common stock (in shares)			(1,230)
Repurchase of common stock		(24,419)	$ (12)			(24,407)
Balance at end of period (in shares) at Dec. 28, 2018			45,981
Balance at end of period at Dec. 28, 2018		124,155	$ 461	(2,580)	460,264	(314,831)	(19,159)
Balance at beginning of period (in shares) at Sep. 30, 2018			47,080
Balance at beginning of period at Sep. 30, 2018		122,059	$ 472	(2,580)	457,978	(317,373)	(16,438)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		56,504
Other comprehensive (loss) income		(1,754)
Reclassification of stranded tax benefits							(2,333)
Balance at end of period (in shares) at Mar. 29, 2019			46,216
Balance at end of period at Mar. 29, 2019		158,497	$ 463	(2,580)	464,082	(282,943)	(20,525)
Balance at beginning of period (in shares) at Dec. 28, 2018			45,981
Balance at beginning of period at Dec. 28, 2018		124,155	$ 461	(2,580)	460,264	(314,831)	(19,159)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		29,555				29,555
Other comprehensive (loss) income		967					967
Reclassification of stranded tax benefits	[1]	0				2,333	(2,333)
Stock-based compensation		1,834			1,834
Issuance of common stock (in shares)			235
Issuance of common stock		1,986	$ 2		1,984
Balance at end of period (in shares) at Mar. 29, 2019			46,216
Balance at end of period at Mar. 29, 2019		158,497	$ 463	(2,580)	464,082	(282,943)	(20,525)
Balance at beginning of period (in shares) at Sep. 30, 2019			46,955
Balance at beginning of period at Sep. 30, 2019		232,936	$ 471	(2,580)	477,139	(200,396)	(41,698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		34,790				34,790
Other comprehensive (loss) income		5,316					5,316
Stock-based compensation		3,123			3,123
Issuance of common stock (in shares)			524
Issuance of common stock		(2,981)	$ 5		(2,986)
Balance at end of period (in shares) at Dec. 27, 2019			47,479
Balance at end of period at Dec. 27, 2019		272,131	$ 476	(2,580)	477,276	(166,659)	(36,382)
Balance at beginning of period (in shares) at Sep. 30, 2019			46,955
Balance at beginning of period at Sep. 30, 2019		232,936	$ 471	(2,580)	477,139	(200,396)	(41,698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		73,983
Other comprehensive (loss) income		(687)
Balance at end of period (in shares) at Mar. 27, 2020			47,176
Balance at end of period at Mar. 27, 2020		295,434	$ 473	(2,580)	482,399	(142,473)	(42,385)
Balance at beginning of period (in shares) at Dec. 27, 2019			47,479
Balance at beginning of period at Dec. 27, 2019		272,131	$ 476	(2,580)	477,276	(166,659)	(36,382)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		39,193				39,193
Other comprehensive (loss) income		(6,003)					(6,003)
Stock-based compensation		4,523			4,523
Issuance of common stock (in shares)			91
Issuance of common stock		601	$ 1		600
Repurchase of common stock (in shares)			(394)
Repurchase of common stock		(15,011)	$ (4)			(15,007)
Balance at end of period (in shares) at Mar. 27, 2020			47,176
Balance at end of period at Mar. 27, 2020		$ 295,434	$ 473	$ (2,580)	$ 482,399	$ (142,473)	$ (42,385)

[1] Due to the adoption of ASU 2018-02.